Navigation Apparatus Capable of Providing Real-Time Navigation Images

ABSTRACT

A navigation apparatus is capable of image-capturing and is used to implement a navigation method including the steps of: a) obtaining current location information associated with the navigation apparatus, and location information of a reference target along a planned route that is being traversed; b) capturing real-time navigation images of the planned route according to an image-capture configuration parameter; c) obtaining a display screen position associated with the reference target with reference to the current location information, the target location information, and the image-capture configuration parameter; and d) showing on the display device the navigation images together with a mark corresponding in position to the display screen position.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority of Taiwanese Application No. 099112666,filed on Apr. 22, 2010.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a navigation apparatus, moreparticularly to a navigation apparatus capable of providing real-timenavigation images.

2. Description of the Related Art

Conventional navigation devices, when approaching a reference targetalong a planned route that is being traversed, are generally configuredto display a two-dimensional schematic image of the planned route withmarks and navigation information thereon. A user has to compare theactual view of the planned route with the schematic image, which mayappear very different from the actual view and thus be confusing.

In recent years, several navigation service providers have been creatingthree-dimensional schematic images of reference targets such asintersections, bridges, and roundabouts for better navigationalexperiences. However, due to high costs, it has been virtuallyimpossible for the navigation service providers to create athree-dimensional schematic image for every reference target. As aresult, navigations toward some reference targets still rely upontwo-dimensional schematic images.

Furthermore, since updating of the three-dimensional schematic images inresponse to removal or reconstruction of geographic objects near therespective reference targets can be costly and time-consuming,navigation toward these reference targets may sometimes be even moreconfusing.

SUMMARY OF THE INVENTION

Therefore, an object of the present invention is to provide a navigationapparatus capable of alleviating the above drawbacks of the prior art.

Accordingly, a navigation apparatus of the present invention includes:

a navigation unit for providing navigation information associated with aplanned route that is being traversed, the navigation informationincluding target location information of a reference target along theplanned route;

an inertial navigation system for detecting motions and rotationsexperienced by the navigation apparatus when the planned route is beingtraversed and for generating inertial navigation data accordingly;

a location-estimating unit for receiving the inertial navigation datagenerated by the inertial navigation system, and configured forobtaining current location information associated with the navigationapparatus with reference to the inertial navigation data;

an image-capturing unit operable for capturing real-time navigationimages of the planned route according to an image-capture configurationparameter;

an image-processing unit coupled to the image-capturing unit forreceiving the navigation images therefrom;

a display device coupled to the image-processing unit; and

a position determining unit for obtaining a display screen positionassociated with the reference target with reference to the currentlocation information, the target location information, and theimage-capture configuration parameter, the position determining unitproviding the display screen position to the image-processing unit, theimage-processing unit controlling the display device to show thenavigation images captured by the image-capturing unit together with amark corresponding in position to the display screen position.

Another object of the present invention is to provide a navigationmethod to be implemented by a navigation apparatus that is capable ofimage-capturing.

Accordingly, the navigation method of the present invention includes thesteps of:

a) obtaining current location information associated with the navigationapparatus, and target location information of a reference target along aplanned route that is being traversed;

b) capturing real-time navigation images of the planned route accordingto an image-capture configuration parameter;

c) obtaining a display screen position associated with the referencetarget with reference to the current location information, the targetlocation information, and the image-capture configuration parameter; and

d) showing on a display device the navigation images together with amark corresponding in position to the display screen position.

BRIEF DESCRIPTION OF THE DRAWINGS

Other features and advantages of the present invention will becomeapparent in the following detailed description of the preferredembodiment with reference to the accompanying drawings, of which:

FIG. 1 is a block diagram of the preferred embodiment of a navigationapparatus according to the present invention;

FIG. 2 is a flowchart illustrating steps of the preferred embodiment ofa navigation method according to the present invention;

FIG. 3 is a schematic diagram illustrating a reference target along aplanned route;

FIG. 4 is a schematic diagram illustrating a navigation image capturedby an image-capturing unit of the navigation apparatus;

FIG. 5 is a schematic diagram to illustrate a navigation bearing of amotor vehicle, in which the navigation apparatus is disposed,approaching the reference target, and a distance between the motorvehicle and the reference target;

FIG. 6 is a diagram to illustrate a relationship between the referencetarget and a display screen position; and

FIG. 7 is a schematic diagram illustrating display of the navigationimage on a display device together with a mark that corresponds inposition to the display screen position.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIG. 1, the preferred embodiment of a navigation apparatus100 according to the present invention is installed in a motor vehicle,and includes a navigation unit 1, an inertial navigation system 2, adisplay device 3, a location-estimating unit 4, a position determiningunit 5, an image-capturing unit 61, an image-processing unit 62, and amemory unit 7.

The navigation unit 1 is configured to obtain a planned route between acurrent location, which is obtained from Global Positioning System (GPS)signals received thereby, and a user-input destination location. Theplanned route may be an optimal route or a shortest route, depending onuser configuration, and is to be traversed by the motor vehicle. Thenavigation unit 1 is coupled to the location-estimating unit 4 forproviding navigation information associated with the planned routethereto. When the motor vehicle is traversing the planned route, thenavigation information includes target location information of areference target to which the motor vehicle is approaching along theplanned route.

The inertial navigation system 2 is coupled to the location-estimatingunit 4 for receiving an inertia-detect signal therefrom, is responsiveto the inertia-detect signal so as to detect motions and rotationsexperienced by the navigation apparatus 100 when the planned route isbeing traversed by the motor vehicle, is configured to generate inertialnavigation data accordingly, and is configured to provide the inertialnavigation data to the location-estimating unit 4.

Referring to FIG. 2, the location-estimating unit 4, the positiondetermining unit 5, the image-capturing unit 61, the image-processingunit 62, and the memory unit 7 will be described hereinafter inconnection with the preferred embodiment of a navigation methodimplemented by the navigation apparatus 100, according to the presentinvention.

In step S11, the navigation unit 1 is configured to provide thenavigation information, which includes the target location informationof the reference target, to the location-estimating unit 4. In thisembodiment, the reference target is a junction of roads indicated by thesolid arrow in FIG. 3.

In step S12, the location-estimating unit 4 is operable to generate theinertia-detect signal so as to cause the inertial navigation system 2 togenerate the inertial navigation data, is operable to receive theinertial navigation data from the inertial navigation system 2, and isconfigured to obtain current location information associated with thenavigation apparatus 100 with reference to the inertial navigation data.The location-estimating unit 4 is further coupled to the memory unit 7to provide the current location information and the target locationinformation thereto for storage therein.

It is to be noted that the target location information includescoordinates and altitude of the reference target, and that the currentlocation information includes coordinates, altitude, and navigationbearing of the navigation apparatus 100.

In step S13, the location-estimating unit 4 is configured to compare adifference in the coordinates included in the target locationinformation and the current location information. If the difference inthe coordinates is indicative of the navigation apparatus 100 beingwithin a predetermined distance, say 100 m, from and approaching thereference target, the navigation apparatus 100 is configured to performsteps S14 and S15.

In step S14, the image-capturing unit 61 is controlled to capturereal-time navigation images of the planned route (see FIG. 4) accordingto an image-capture configuration parameter, which is pre-stored in thememory unit 7 and specifies the focal length at which the navigationimages are captured by the image-capturing unit 61. The image processingunit 62 is coupled to the image-capturing unit 61 for receiving thenavigation images therefrom, and is coupled to the display device 3.

In step S15, the position determining unit 5, which is coupled to thememory unit 7, receives the target location information, the currentlocation information, and the image-capture configuration parameter fromthe memory unit 7, and is configured to obtain a display screen positionassociated with the reference target with reference to the targetlocation information, the current location information, and theimage-capture configuration parameter.

Referring to FIG. 5, the dashed-line shows a portion of the plannedroute being traversed by the motor vehicle. “D” is a distance betweenthe navigation apparatus 100 and the reference target, and is thedifference in coordinates thereof. “a” is an angle obtained from thenavigation bearing of the navigation apparatus 100 with reference to thecoordinates of the navigation apparatus 100 and the reference target.The position determining unit 5 is configured to calculate “Y” and “X”using the equations of:

X=D×sin (a)

Y=D×cos (a)

Referring to FIG. 6, “dH” is a difference in altitude between thereference target and the navigation apparatus 100, “f” is the focallength at which the navigation images are captured by theimage-capturing unit 61, “(x, h)” is the Cartesian coordinatesassociated with a sensor pixel of the image-capturing unit 61 thatcorresponds to the reference target, and “(px, py) ” is the Cartesiancoordinates associated with a display pixel of a display panel of thedisplay device 3 that corresponds to the reference target.

The position determining unit 5 is configured to obtain “dH” bycomparing the altitudes of the reference target and the navigationapparatus 100, and to obtain “(x, h)” using the equations of:

x=f×X/Y

h=f×dH/Y

Finally, the position determining unit 5 is configured to obtain “(px,py)” using the equations of:

px=x×pW/cW

py=h×pH/cH

In step S16, the positioning determining unit 5, which is furthercoupled to the image-processing unit 62, controls the image-processingunit 62 to show on the display panel of the display device 3 thenavigation images captured by the image-capturing unit 61 together witha mark corresponding in position to the display screen position (seeFIG. 7).

It is worth noting that the position determining unit 5 is configured toobtain a display screen position for each navigation image such that themark corresponds in position to the display screen position in eachnavigation image.

In step S17, the location-estimating unit 4 is configured to determinewhether the navigation apparatus 100 has moved past the reference targetaccording to the difference in the coordinates included in the targetlocation information and the current location information, and toproceed to step S18 if affirmative.

In step S18, the position determining unit 5 is configured to controlthe image-processing unit 62 to stop display of the navigation imagesand the mark on the display panel of the display device 3, and toproceed to step S19.

In step S19, the navigation unit 1 is configured to determine whetherthe navigation apparatus 100 has yet to arrive at the user-inputdestination location, and to proceed to step S11 for navigation toward anext reference target along the planned route if affirmative.

In summary, the navigation apparatus 100 is operable to perform thenavigation method of the preferred embodiment, according to the presentinvention, for displaying the navigation images together with the markcorresponding in position to the display screen position, which isrelatively intuitive and effective even if geographic objects near therespective reference targets undergo changes or are removed.

While the present invention has been described in connection with whatis considered the most practical and preferred embodiment, it isunderstood that this invention is not limited to the disclosedembodiment but is intended to cover various arrangements included withinthe spirit and scope of the broadest interpretation so as to encompassall such modifications and equivalent arrangements.

1. A navigation apparatus comprising: a navigation unit for providingnavigation information associated with a planned route that is beingtraversed, the navigation information including location information ofa reference target along the planned route; an inertial navigationsystem for detecting motions and rotations experienced by saidnavigation apparatus when the planned route is being traversed and forgenerating inertial navigation data accordingly; a location-estimatingunit for receiving the inertial navigation data generated by saidinertial navigation system, and configured for obtaining currentlocation information associated with said navigation apparatus withreference to the inertial navigation data; an image-capturing unitoperable for capturing real-time navigation images of the planned routeaccording to an image-capture configuration parameter; animage-processing unit coupled to said image-capturing unit for receivingthe navigation images therefrom; a display device coupled to saidimage-processing unit; and a position determining unit for obtaining adisplay screen position associated with the reference target withreference to the current location information, the target locationinformation, and the image-capture configuration parameter, saidposition determining unit providing the display screen position to saidimage-processing unit, said image-processing unit controlling saiddisplay device to show the navigation images captured by saidimage-capturing unit together with a mark corresponding in position tothe display screen position.
 2. The navigation apparatus as claimed inclaim 1, wherein: the location information includes coordinates andaltitude of the reference target; the current location informationincludes coordinates, altitude, and navigation bearing of saidnavigation apparatus; the image-capture configuration parameterspecifies the focal length at which the navigation images are capturedby said image-capturing unit; and said position determining unit isconfigured to obtain the display screen position from the image-captureconfiguration parameter, the navigation bearing, a difference in thecoordinates included in the location information and the currentlocation information, and a difference in the altitudes included in thelocation information and the current location information.
 3. Thenavigation apparatus as claimed in claim 2, wherein said positiondetermining unit is configured to control said image-processing unit toshow the navigation images on said display device together with the markwhen the difference in the coordinates included in the locationinformation and the current location information is indicative of saidnavigation apparatus being within a predetermined distance from andapproaching the reference target.
 4. The navigation apparatus as claimedin claim 3, wherein said position determining unit is further configuredto control said image-processing unit to stop display of the navigationimages and the mark on said display device when said positiondetermining unit determines that said navigation apparatus has movedpast the reference target according to the difference in the coordinatesincluded in the location information and the current locationinformation.
 5. The navigation apparatus as claimed in claim 1, furthercomprising a memory unit for storing the current location informationobtained by said location-estimating unit, the location informationprovided by said navigation unit, and the image-capture configurationparameter, said position determining unit being coupled to said memoryunit for accessing the current location information, the target locationinformation, and the image-capture configuration parameter storedtherein.
 6. A navigation method to be implemented by a navigationapparatus that is capable of image-capturing and that has a displaydevice, said navigation method comprising the steps of: a) obtainingcurrent location information associated with the navigation apparatus,and location information of a reference target along a planned routethat is being traversed; b) capturing real-time navigation images of theplanned route according to an image-capture configuration parameter; c)obtaining a display screen position associated with the reference targetwith reference to the current location information, the target locationinformation, and the image-capture configuration parameter; and d)showing on the display device the navigation images together with a markcorresponding in position to the display screen position.
 7. Thenavigation method as claimed in claim 6, wherein: the locationinformation includes coordinates and altitude of the reference target;the current location information includes coordinates, altitude, andnavigation bearing of the navigation apparatus; the image-captureconfiguration parameter specifies the focal length at which thenavigation images are captured by the navigation apparatus; and in stepc) , the display screen position is obtained from the image-captureconfiguration parameter, the navigation bearing, a difference in thecoordinates included in the location information and the currentlocation information, and a difference in the altitudes included in thelocation information and the current location information.
 8. Thenavigation method as claimed in claim 7, wherein the navigationapparatus is configured to perform step d) when the difference in thecoordinates included in the location information and the currentlocation information is indicative of the navigation apparatus beingwithin a predetermined distance from and approaching the referencetarget.
 9. The navigation method as claimed in claim 8, furthercomprising the step of: e) stopping display of the navigation images andthe mark on the display device when the difference in the coordinatesincluded in the location information and the current locationinformation is indicative of the navigation apparatus having moved pastthe reference target.
 10. The navigation method as claimed in claim 6,the navigation apparatus including a memory unit, wherein the currentlocation information and the location information obtained in step a),together with the image-capture configuration parameter, are stored inthe memory unit for subsequent use in step c).